1. Check the ‘send/ receive’ settings in Outlook to make sure emails are being sent, received, and properly sorted.

2. Check the Outlook account settings and confirm the correct email accounts are connected to Outlook.

3. Check the inbox rules in Outlook and make sure they are set up correctly.

4. Search through folders and check for any emails that may have been moved or deleted.

5. Make sure your Outlook is updated to the latest version.